Method of fabricating slush pump fluid end housings



March 8, 1966 A. R. REINARZ METHOD OF FABRICATING SLUSH PUMP FLUID ENDHOUSINGS 4 Sheets-Sheet 1 Filed Jan. 7, 1963 INVENTOR Alvin R. ReinorzATTORNEXG REINARZ 3,238,604

SLUSH PUMP FLUID END HOUSINGS March 8, 1966 METHOD OF FABRICATING 4Sheets-Sheet 2 Filed Jan.

lNVEIyTOR Alvm R. Relnurz ATTORNEY March 8, 1966 A. R. REINARZ 3,238,604

METHOD OF FABRICATING SLUSH PUMP FLUID END HOUSINGS Filed Jan. 7, 1963 4Sheets-Sheet 5 INVENTOR Alvin R. Remarz BY M564 ATTORNEYS March 8, 1966A. R. REINARZ METHOD OF FABRICATING SLUSH PUMP FLUID END HOUSINGS FiledJan. 7, 1963 4 Sheets-Sheet 4 6 M 5 I U 4 H 3 mu r w w A 2 a imr u n 26% Q Q 5 n /9 F 4 O O O O O O o l O OO O O O O O O O O O O o 6 lINVENTOR Alvin R. Reinurz BY M ATTORNEY United States Patent 3,238,604METHOD OF FABRICATING SLUSH PUMP FLUID END HOUSINGS Alvin R. Reinarz,Gainesville, Tex., assignor to Armco Steel Corporation, Middletown,Ohio, a corporation of Ohio Filed Jan. 7, 1963, Ser. No. 249,771 11Claims. (Cl. 29156.4)

This invention relates to the fluid end of a slush pump adapted for usein the oil industry, and more particularly to a method of fabricatingthe fluid end housing for such a slush pump.

It is common practice in drilling oil wells to utilize a drill bitconnected to the lower end of a drill pipe which extends from thesurface of the earth down to the bottom of the well. The drill bit anddrill pipe are rotated by suitable equipment above ground. Also locatedabove ground is a slush pump connected to pump drilling fluid into theupper end of the drill pipe. The slush pump forces the drilling fluiddown to the bottom of the well through the drill pipe, through the drillbit, and then back up to the surface of the earth in the space outsidethe drill pipe.

As the sources of oil closer to the surface of the earth becomedepleted, it becomes necessary to drill deeper wells which, in turn,require slush pumps capable of delivering drilling fluid at higherpressures. Further demands for increased drilling fluid pressures arebrought about by the trend toward jet drill bits which direct thedrilling fluid through relatively small high pressure nozzles. The fluidend housing of a slush pump must be constructed to withstand theseincreased pressures. In the smaller slush pumps, the housing can easilybe fabricated from a casting, but as the pressure requirements increase,it becomes increasingly diflicult to use castings because of theincreased physical size and the inherent poor metallurgicalcharacteristics. Forged housings, on the other hand, have much bettermetallurgical properties and reduce the physical size of the housing forcomparable specifications. Forged housings, however, are considerablymore expensive than cast housings and, hence, are difficult to market atcompetitive prices.

Thus, an object of the invention is to provide a method of fabricating afluid end housing for a slush pump from forged components whileminimizing the cost increase over comparable cast housings.

Another object is to provide a method of fabricating a fluid end housingusing pluralities of identical forged blanks so as to minimize thenumber of different required forging operations, and to minimize thenumber of different component parts stocked in inventory.

Still another object is to provide a method of fabricating a fluid endhousing using pluralities of identically forged blanks which aresubsequently machined to different dimensions so that an identicalforging can be utilized in the plurality of different positions.

Yet another object is to provide a method of fabricating a fluid endhousing by assembling a relatively large number of individual componentsand yet achieving accurate internal dimensions extending through morethan a single one of these components.

The invention is specifically illustrated with respect to the fluid endfor a dual cylinder, double acting type slush pump, but the invention isnot limited to any particular type of pump construction. In accordancewith this invention, the housing for such a fluid end is fabricated fromfour identical forged cylinder barrel half blanks, eight identicalforged valve pot blanks, a cast suction manifold and a cast dischargemanifold. Each of the barrel half blanks are machined to somewhatdifferent di- Patented Mar. 8, 1966 mensions to form four differentbarrel halves which, when assembled, will form the two fluid cylindersof the fluid end. During the machining operation, a suction port and adischarge port are provided in each of the barrel halves. Half of thevalve pot blanks are machined to form suction valve pots, and the otherhalf are machined to form the discharge valve pots. At this point, itshould be noted that the two basic types of forgings have now beenmachined and form six different component parts.

A suction valve pot and a discharge valve pot are securely welded toeach of the barrel halves so as to properly communicate with the suctionand discharge ports respectively, thus forming quarter sub-assemblies.The barrel halves are then welded together to form two halfsub-assemblies, each half sub-assembly including a complete fluidcylinder. Next, the suction and discharge manifolds are secured inposition to complete the assembly. After all welding operations arecompleted, the entire unit is stress relieved, and finally the fluidcylinders are machined to their final and precise internal dimensions.

A better understanding of the invention, with respect to the foregoingand other objects, can be achieved by referring to the followingspecification and drawings, the drawings forming a portion of thespecification and wherein:

FIG. 1 is a view in exploded perspective showing the forming of quartersub-assemblies and half sub-assemblies in accordance with the method ofthe present invention;

FIG. 2 is a view in partial exploded perspective showing the relativepositions of components forming the completed half sub-assemblies andthe manner in which the manifolds are added to complete the assembly ofthe fluid end housing;

FIG. 3 is a view in perspective of a forged cylinder barrel half blank;

FIG. 4 is a view in perspective of a rough machined cylinder barrelhalf;

FIG. 5 is a view in perspective of a forged valve pot blank;

FIG. 6 is a view in perspective of a machined suction valve pot;

FIG. 7 is an end elevational view, partly in section, of a completedfluid end housing fabricated in accordance with the method of thepresent invention; and

FIG. 8 is a sectional view looking along lines 88 of FIG. 7.

As shown in FIGS. 1, 2, 7 and 8, a fluid end housing 1 fabricated by themethod of the present invention includes four different cylinder barrelhalves 2, 3, 4 and 5; four identical suction valve pots 6; fouridentical discharge valve pots 7; a suction manifold 8; and a dischargemanifold 9. The fluid end housing illustrated is for a duplex, doubleacting slush pump and has a head end It) and a rod end 11. As viewedfrom the rod end, cylinder barrel halves 2 and 5, when assembled, form aright-hand fluid cylinder 12, and cylinder barrel halves 3 and 4similarly form a left-hand fluid cylinder 13.

An initial step in fabricating fluid end assembly 1 is forging fouridentical cylinder barrel half blanks 14 (FIG. 3) from a suitable steelingot. Each cylinder barrel half blank is generally cylindrical, havinga center body portion 15, a larger diameter flange 16 at one end of theblank, and a smaller diameter elongated cylindrical portion 17 at theother end. Projecting radially from the same point along thelongitudinal axis of center body portion 15 are two identical, generallycylindrical bosses 18 and 19 which are at right angles to one another.The cylinder barrel half blanks are provided with longitudinallyextending circular openings 20 to reduce subsequent machining.

One of the forged steel cylinder barrel half blanks is subsequentlymachined to form cylinder barrel half 2 (FIG. 1). A barrel half blank 14is bored longitudinally to enlarge circular opening 20 and form a roughmachined bore 21 having a configuration as can be seen in FIG. 8. Boss18 is drilled to form a radially extending suction port 22 communicatingwith bore 21, and boss 19 is drilled to form a radially extendingdischarge port 23 which also communicates with bore 21. Discharge port23 has a larger diameter than suction port 22 and extends at rightangles thereto. The plane surfaces of bosses 18 and 19 are machined toprovide beveled surfaces 24 and 25 which, when assembled, will form anannular V-shaped groove with an adjacent component. The groove so formedis adapted to receive a weld fillet, as will be subsequently described.The plane end surface of elongated portion 17 is similarly machined toprovide a bevel surface 26 around bore 21. The flat end face of flange16 is face machined to form a plane surface perpendicular to the axis ofcylinder barrel half 2.

As best seen in FIG. 1, cylinder barrel half 2 forms the right-hand,head end, cylinder barrel half of fluid end housing 1. Another of theforged cylinder barrel half blanks is similarly machined to form theleft-hand, head end, cylinder barrel half 3. The essential difference inmachining is that the smaller diameter suction port is drilled throughboss 19, and the larger diameter discharge port is drilled through boss18 so that, when cylinder barrel half 3 is properly oriented, suctionport 22 faces upwardly and discharge port 23 faces to the left (FIG. 1).It should be noted that bosses 18 and 19 on the forged cylinder barrelhalf blanks are both sufliciently large to permit the larger diameterdischarge port to be drilled in either boss.

The right-hand, rod end, cylinder barrel half of fluid end housing 1 isalso machined from a forged cylinder barrel half blank 14. In this case,the flange end of the blank is drilled to form a bore 27 at the rod endof housing which is of smaller diameter than a similar bore at the headend of the assembly. The interior of the blank is rough machined toconform generally to the configuration shown in FIG. 8. Boss 22 isdrilled to form a suction port and boss 23 is drilled to form adischarge port and the plane surfaces of the bosses are machined toprovide beveled surfaces. The right-hand, rod end, cylinder barrel half4 of the housing is machined similar to cylinder barrel 5 except thatboss 23 is drilled to form the suction port and boss 22 is drilled toform the discharge port. When cylinder barrel halves 4 and 5 areproperly orientated, as shown in FIG. 1, the discharge ports extendvertically and the suction ports extend horizontally away from oneanother.

All four suction valve pots 6 and all four discharge pots 7 are machinedfrom eight identical forged valve pot blanks 29 (FIG. 3). Valve potblank 29 has a cylindrical body 30 with a circular opening 31 extendingthrough the body along the longitudinal axis. A cylindrical boss 32projects radially from body 30 and is located slightly offset toward oneend of the cylindrical body.

-F our suction valve pots are finish machined from valve pot blanks 29by boring a cylindrical outlet passage 33 through boss 32 to the centerof the blank. The blank is then further machined, enlarging opening 31,to form an inlet passage 33, at the lower end, and a valve chamber 34.The upper end of the blank is internally threaded to provide threads 35adapted to receive a threaded plug (not shown) for closing the upper endof the valve pot. The bottom end of the valve pot blank is faced toprovide a plane surface perpendicular to the axis of cylindrical body30. The face of boss 32 is machined to provide a beveled surface 36.

passage 38, outlet passage 39 and valve chamber 40 of discharge valvepot 7 are substantially identical to the same corresponding portions ofthe suction valve pot. The upper end of discharge valve pot 7 isinternally threaded to provide threads 41 that are adapted to receive aplug for closing the valve chamber. The face of boss 32 is machined toprovide a beveled surface 42 surrounding outlet passage 39.

The preferred assembly procedure is to first form quarter sub-assembliesby welding a suction valve pot 6 and a discharge valve pot 7 to each ofthe machined barrel halves. To form the right-hand, head end, quartersub-assembly 43 (FIG. 1), outlet passage 33 of a suction valve pot 6 isaligned with suction port 22 of cylinder barrel half 2 and the membersare secured to one another by welding together the beveled surfaces 36and 24. A discharge valve pot 7 is positioned with inlet passage 38aligned with discharge port 23 and beveled surfaces 25 and 37 are thenjoined by Welding. The additional quarter sub-assemblies are formed inlike fashion including, respectively, barrel halves 3, 4 and 5. Halfsubassembly 44 is formed by axially aligning cylinder barrel halves 2and 5 and by then welding the cylinder barrel halves to one another byfilling the V-shaped annular groove formed by adjacent beveled surfaceswith a weld fillet. Half sub-assembly 44 is formed in like fashion bysimilarly joining cylinder barrel halves 3 and 4. The longitudinalopening passing through half sub-assemblies 44 and 44' form,respectively, the right and left fluid cylinders.

Discharge manifold 9 (FIG. 2) is an integrally cast unit cored in asuitably dimensioned cored mold. The discharge manifold includes atubular H-shaped portion formed by a conduit 46 which, in the completedvassembly, is adapted to extend along an axis parallel to the fluidcylinders 12 and 13, and a pair of communicating, horizontal crossconduits 47 and 48 at the ends thereof. The internal diameter of theconduits is approximately the same as that of the outlet passages ofdischarge valve pots 7 and the lengths of the conduits are such that theopen ends of cross conduits 47 and 48 will align with these outletpassages in the completed assembly. Preferably, the freeends of thecross conduits are machined to provide a beveled surface which will forman annular V-shaped welding groove with the beveled surfaces 42 of theadjacent valve pot 7. An upwardly extending conduit 44, at one end, isjoined to conduit 46 at the midpoint and, at the other end, terminatesin a flange 45. Flange 45 is machined to provide a finished planehorizontal surface, and is drilled to provide a circulary array ofdownwardly directed bolt holes.

Suction manifold 8 is also an integral casting formed in a suitablycored mold. The suction manifold includes a header formed. by a pair ofhorizontally disposed Y-shaped conduit portions 51a and 5111, eachhaving a pair of upwardly extending conduit portions 50 at the divergentends. The base legs of the Y-shaped conduit portions, as viewed in FIG.2, form a single conduit having a longitudinal axis perpendicular to thefluid cylinders 12 and 13 and having a horizontal, rearwardly extendingconduit 49 extending from the midpoint thereof. The free end of conduit49, and the free ends of conduits 50 terminate in flanged end portionswhich are machined to provide a finished plane surface and drilled toprovide a circular array of bolt holes perpendicular to the planesurfaces. The suction manifold is dimensioned so that the four upwardlyextending conduit potrions 50 will communicate respectively with theinlet passages 33' of the corresponding suction valve pots 6.

The half sub-assemblies 44 and 44' (FIG. 1) are secured to one anotherby means of suitably dimensioned spacers 57 (FIG. 2) welded between theflanged end portions of the cylinder barrel halves. Discharge manifold 9is then lowered into position with the longitudinal axes of crossconduits 47 and 48 extending through the re spective outlet passages ofdischarge valve pots 7. The discharge manifold is then welded intoposition thereby forming a weld fillet in the V-shaped grooves formed byadjacent beveled surfaces.

At this point in the fabrication, it should be noted that all weldingoperations have been completed. Each of the welds are carefullyinspected by suitable nondestructive methods and defective Weldsrepaired if possible. The entire unit is then stress relieved toeliminate stresses caused by the various welding operations. The stressrelieving operation entails slowly heating the unit to a suitable stressrelieving temperature, maintaining the temperature for a predeterminedperiod of time, and. then slowly cooling the unit.

The welding operations and subsequent stress relieving may cause theassembly to warp and therefore the finish machining of the fluidcylinder interiors and of the surfaces which connect to the suctionmanifold must be deferred until the stress relieving is completed.During the final machining operations of fluid cylinder 12, the annularribs 60 and 61 (FIG. 8) are precisely machined so that a cylinder liner(not shown) to be supported by these ribs, will be accurately alignedeven though these ribs are part of different cylinder barrel halves. Thehead end of the fluid cylinder 12, including chamber 58, is finishedmachined and a circumferential array of bolt holes 62 are drilled andtapped in flange 16 so that a head assembly (not shown) can be securelybolted to the head end with the proper alignment. The rod end of thefluid cylinder is also finished machined and a double row ofcircumferentially arranged bolt holes 63 are drilled and tapped so thata rod end assembly can be securely bolted thereto in a properly alignedrelationship. The other fluid cylinder 13 is finish machined in likefashion.

The lower plane surfaces of the four suction valve pots 6 are faced. anda circular array of bolt holes 64 are drilled and tapped extendingupwardly from the lower surface. The final step in the assemblyoperation is to move suction manifold 8 (FIG. 2) upwardly againstsuction valve pots 6 so that the conduits 50 are aligned with the inletpassages of the suction valve pots. The suction manifold is then boltedinto position by means of suitable bolts 65.

The fluid end is completed. by mounting a pressure actuated check valvein each of the valve pots, and a piston, a cylinder lining, a rod endassembly and head end assembly in each of the fluid cylinders. Thepistons are preferably staggered so that there are four power strokesfor each cycle of operation. In between the valves, i.e., including thefluid cylinders and a portion of the valve pots, there are violentpressure fluctuations, changing from a high negative pressure during thesuction stroke to a high positive pressure during the power stroke. Thesurrounding portion of the housing must be capable of withstanding thesepressure fluctuations and therefore the fluid cylinders and valve potsare made from forged blanks which have much better metallurgicalproperties than do castings. The pressure fluctuations are substantiallyless outside the valves since the pressure is either positive ornegative, but does not change, and since the staggered four strokes percycle further decrease the fluctuations. Accordingly, castings suflicefor the suction and discharge manifolds.

The method in accordance with this invention permits the entire fluidend housing to be fabricated from two types of relatively simpleforgings and two castings, thereby providing a housing better capable ofwithstand.- ing the high pressures and pressure fluctuation while at thesame time minimizing the increase in cost over comparable completelycast housings.

While the invention has been illustrated with respect to a particulartype of slush pump fluid end, it should be clear that the invention isapplicable to slush pumps generally. Furthermore, there are numerousmodifications which can be made in the method without departing from thescope of the invention. The scope is more particularly defined in theappended claims.

What is claimed is:

1. The method of fabricating a fluid end housing assembly for a slushpump comprising,

forging a plurality of identical valve pot blanks, and

a plurality of identical cylinder barrel half blanks;

machining said cylinder barrel half blanks to form at least one pair ofcylinder barrel halves, which pair can be assembled into a fluidcylinder having at least one suction port and at least one dischargeport, and

said valve pot blanks to form suction valve pots and discharge valvepots which, when assembled, will communicate with said suction anddischarge ports respectively;

welding said suction and discharge valve pots to said cylinder barrelhalves so as to communicate, respectively, with said suction anddischarge ports, and

said pair of cylinder barrel halves together to form a fluid cylinder;

stress relieving said welded assembly; and

then finish machining the interior of said fluid cylinder.

2. The method of fabricating a fluid end housing for a slush pump,comprising forging four identical cylindrical half blanks each having apair of identical bosses near one end extending radially outwardly fromthe longitudinal axis of the blank and at right angles to one another;

machining said four half blanks so that when assembled they form twosubstantially parallel fluid cylinders in a horizontal plane, each ofsaid fluid cylinders having a pair of suction ports near the endsthereof extending away from the other fluid cylinder and through bosseson said half blanks, and

a pair of discharge ports also near the ends thereof but extendingupwardly through the remaining bosses;

Welding a previously forged and machined suction valve pot to each ofsaid half blanks so as to communicate with each of said suction ports;

welding a previously forged and machined discharge valve pot to each ofsaid half blanks so as to communicate with each of said discharge ports;

welding said machined half blanks together to form two fluid cylinders;

a casting a suction and a discharge manifold and connecting the same tocommunicate, respectively, with said suction and discharge valve pots.

3. The method of fabricating in accordance with claim 2 wherein theassembled unit is stress relieved after all welding operations arecompleted and wherein said fluid cylinders are finish machined aftersaid assembled unit is stress relieved.

4. The method of fabricating in accordance with claim 2 wherein saidsuction valve pots and said discharge valve pots are machined fromidentical forged blanks.

5. The method of fabricating a fluid end housing for a slush pump,comprising forging four identical cylinder barrel half blanks and eightidentical valve pot blanks machining each of said cylinder barrel halfblanks to provide a suction port and a discharge port therein machiningsaid valve pot blanks to form suction valve pots and discharge valvepots forming quarter sub-assemblies by welding a suction valve pot and adischarge valve to each of said cylinder barrel halves to communicatewith the associated port forming half sub-assemblies by welding togethersaid cylinder barrel halves to form two fluid cylinders casting asuction manifold and a discharge manifold connecting said suctionmanifold to communicate with each of said suction valve pots; and

connecting said discharge manifold to communicate with each of saiddischarge valve pots.

6. The method of fabricating in accordance with claim wherein saiddischarge manifold is welded to said discharge pots and wherein theassembly is stress relieved after all welding operations are completedand said fluid cylinders are finish machined internally after theassembly is stress relieved.

7. The method of fabricating a fluid end housing for a slush pump,comprising forging four identical cylinder barrel half blanks;

forging eight identical valve pot blanks;

machining said valve pot blanks to form valve pots having an inlet ofone diameter and an outlet of another diameter welding two valve pots toeach of said cylinder barrel halves so that the outlet of one of saidwelded valve pots communicates with the suction port, and

the inlet of the other welded valve pot communicates with the dischargeport;

welding together said cylinder barrel halves to form two fluidcylinders;

casting a suction manifold and connecting the same to communicate withthe inlets of the valve pots welded to communicate with said suctionports; and

casting a discharge manifold and connecting the same to communicate withthe outlets of said valve pots welded to communicate'with said dischargeports.

8. The method in accordance with claim 7 wherein the inlets and outletsof the valve pots which communicate with said discharge ports aremachined having beveled surfaces suitable for welding;

the outlets of the valve pots which communicate with said suction portsare similarly beveled;

said discharge manifold is welded into position; and

said suction manifold is bolted into position.

9. The method in accordance with claim 7 wherein the assembly is stressrelieved after all welding operations are completed; and

said fluid cylinders are thereafter finished machined internally.

10. The method of fabricating a fluid end housing for a slush pump,comprising 8 forging four identical cylinder barrel half blanks eachhaving a pair of similarly dimensioned bosses near one end extendingradially outwardly from the longitudinal axis of the blank and at rightangles with one another; forging eight identical valve pot blanks eachhaving a boss extending outwardly perpendicular to the longitudinalaxis; machining four of said valve pot blanks to form suction valve potseach having an inlet of one diameter concentric with said longitudinalaxis, and an outlet of another diameter extending through the bossthereof, the material surrounding said outlets being beveled to providea surface suitable for welding; similarly machining the remaining valvepot blanks to form discharge valve pots and in addition beveling thematerial surrounding said inlets to provide a surface suitable forwelding; machining said four cylinder barrel half blanks to formcylinder barrel halves so that when assembled they form twosubstantially parallel fluid cylinders in a horizontal plane, each ofsaid fluid cylinders having a pair of suction ports of said one diameternear the ends thereof extending away from the other fluid cylinder andthrough bosses on the blanks, and a pair of discharge ports of saidother diameter also near the ends thereof extending upwardly through theremaining bosses;

Welding said discharge pots so that the inlets thereof each communicatewith a different discharge port; welding said suction pots so that theoutlets thereof each communicate with a different suction port;

casting a discharge and a suction manifold;

welding said discharge manifold to communicate with the outlet of eachof said discharge pots; and

securing said suction manifold to communicate with the inlet of each ofsaid suction pots.

11. The method in accordance with claim 10 further including the stepsof stress relieving after all welding operations are completed, and

thereafter machining said fluid cylinders to precise internaldimensions.

No references cited.

WHITMORE A. WILTZ, Primary Examiner.

P. M. COHEN, Examiner.

1. THE METHOD OF FABRICATING A FLUID END HOUSING ASSEMBLY FOR A SLUSHPUMP COMPRISING, FORGING A PLURALITY OF IDENTICAL VALVE POT BLANKS, ANDA PLURALITY OF IDENTICAL CYLINDER BARREL HALF BLANKS; MACHINING SAIDCYLINDER BARREL HALF BLANKS TO FORM AT LEAST ONE PAIR OF CYLINDER BARRELHALVES, WHICH PAIR CAN BE ASSEMBLED INTO A FLUID CYLINDER HAVING ATLEAST ONE SUCTION PORT AND AT LEAST ONE DISCHARGE PORT, AND SAID VALVEPOT BLANKS TO FORM SUCTION VALVE POTS AND DISCHARGE VALVE POTS WHICH,WHEN ASSEMBLED, WILL COMMUNICATE WITH SAID SUCTION AND DISCHARGE PORTSRESPECTIVELY; WELDING SAID SUCTION AND DISCHARGE VALVE POTS TO SAIDCYLINDER BARREL HALVES SO AS TO COMMUNICATE, RESPECTIVELY, WITH SAIDSUCTION AND DISCHARGE PORTS, AND SAID PAIR OF CYLINDER BARREL HALVESTOGETHER TO FORM A FLUID CYLINDER; STRESS RELIEVING SAID WELDEDASSEMBLY; AND THEN FINISH MACHINING THE INTERIOR OF SAID FLUID CYLINDER.